Methods and apparatus for supporting inter-frequency measurements

Abstract

The invention relates to methods and devices for supporting configuration of a measurement gap pattern for a user equipment requiring measurement gaps for performing an inter-frequency measurement. A radio network node receives an indication from the user equipment that the user equipment is going to perform an inter-frequency measurement for positioning, which inter-frequency measurement requires measurement gaps. The radio network node may determine a measurement gap pattern for performing the inter-frequency measurement and may signal, to the user equipment, information to initiate use of the determined measurement gap pattern in the user equipment. Alternatively the user equipment configures the measurement gap pattern itself based on a set of pre-defined rules.

The invention claimed is: 
     
       1. A method in a radio network node of a wireless communication system of supporting configuration of a measurement gap pattern for a user equipment requiring measurement gaps for performing an inter-frequency measurement for positioning, the method comprising:
 receiving from the user equipment an indication that the user equipment is going to perform an inter-frequency measurement for positioning, which inter-frequency measurement requires measurement gaps. 
 
     
     
       2. The method of  claim 1 , wherein the inter-frequency measurement is a Reference Signal Time Difference, RSTD, measurement. 
     
     
       3. The method of  claim 1 , wherein said received indication includes an indication of a measurement gap pattern that the user equipment needs for performing the inter-frequency measurement. 
     
     
       4. The method of  claim 1 , wherein said received indication includes a subframe number (SFN) offset, a frame offset, a subframe offset, or a subframe gap offset. 
     
     
       5. The method of  claim 1 , wherein the indication includes timing offset information, and wherein the method further comprises using the timing offset information to configure the measurement gap pattern such that sufficient amount of the reference signals to be used for said inter-frequency measurement fall in measurement gaps of the measurement gap pattern. 
     
     
       6. The method of  claim 1 , further comprising transparently forwarding from a network node to the user equipment an indication that the user equipment is requested to start an inter-frequency measurement for positioning, without becoming aware of said indication. 
     
     
       7. A radio network node of a wireless communication system, wherein said radio network node is configured for signal interaction with a user equipment requiring configuration of a measurement gap pattern for performing an inter-frequency measurement, wherein said radio network node comprises a processor and a memory, the memory containing instructions executable by the processor whereby the radio network node is configured to receive from the user equipment an indication that the user equipment is going to perform an inter-frequency measurement for positioning, which inter-frequency measurement requires measurement gaps. 
     
     
       8. The radio network node of  claim 7 , wherein the inter-frequency measurement is a Reference Signal Time Difference, RSTD, measurement. 
     
     
       9. The radio network node of  claim 7 , wherein said indication includes an indication of a measurement gap pattern that the user equipment needs for performing the inter-frequency measurement. 
     
     
       10. The radio network node of  claim 7 , wherein said received indication includes a subframe number (SFN) offset, a frame offset, a subframe offset, or a subframe gap offset. 
     
     
       11. The radio network node of  claim 7 , wherein the indication includes timing offset information, and wherein the memory contains instructions executable by the processor whereby the radio network node is configured to use the timing offset information to configure the measurement gap pattern such that sufficient amount of the reference signals to be used for said inter-frequency measurement fall in measurement gaps of the measurement gap pattern. 
     
     
       12. The radio network node of  claim 7 , wherein the memory contains instructions executable by the processor whereby the radio network node is configured to transparently forward from a network node to the user equipment an indication that the user equipment is requested to start an inter-frequency measurement for positioning, without becoming aware of said indication. 
     
     
       13. A method in a user equipment of a wireless communication system of supporting configuration of a measurement gap pattern for an inter-frequency measurement performed by the user equipment, the method comprising:
 receiving an indication that the user equipment is requested to start an inter-frequency measurement for positioning; and 
 transmitting, to a radio network node, an indication that the user equipment is going to perform an inter-frequency measurement for positioning, which inter-frequency measurement requires measurement gaps. 
 
     
     
       14. The method of  claim 13 , wherein the inter-frequency measurement is a Reference Signal Time Difference, RSTD, measurement. 
     
     
       15. The method of  claim 13 , wherein said transmitted indication includes an indication of a measurement gap pattern that the user equipment needs for performing the inter-frequency measurement. 
     
     
       16. The method of  claim 13 , wherein said transmitted indication includes a subframe number (SFN) offset, a frame offset, a subframe offset, or a subframe gap offset. 
     
     
       17. The method of  claims 13 , wherein said transmitted indication includes timing offset information that can be used to configure the measurement gap pattern such that sufficient amount of the reference signals to be used for said inter-frequency measurement fall in measurement gaps of the measurement gap pattern. 
     
     
       18. The method of  claim 13 , wherein said receiving comprising receiving in a manner that is transparent to the radio network node. 
     
     
       19. A user equipment for use in a wireless communication system, wherein said user equipment is configured for signal interaction with a radio network node, the user equipment comprising:
 a processor and a memory, the memory containing instructions executable by the processor whereby the user equipment is configured to:
 receive an indication that the user equipment is requested to start an inter-frequency measurement for positioning for which the user equipment requires measurement gaps; and 
 transmit, to a radio network node, an indication that the user equipment is going to perform an inter-frequency measurement for positioning, which inter-frequency measurement requires measurement gaps. 
 
 
     
     
       20. The user equipment of  claim 19 , wherein the inter-frequency measurement is a Reference Signal Time Difference, RSTD, measurement. 
     
     
       21. The user equipment of  claim 19 , wherein said memory contains instructions executable by the processor whereby the user equipment is configured to include, in the indication to be transmitted, an indication of a measurement gap pattern that the user equipment needs for performing the inter-frequency measurement. 
     
     
       22. The user equipment of  claim 19 , wherein said transmitted indication includes a subframe number (SFN) offset, a frame offset, a subframe offset, or a subframe gap offset. 
     
     
       23. The user equipment of  claim 19 , wherein said memory contains instructions executable by the processor whereby the user equipment is configured to include, in the indication to be transmitted, timing offset information that can be used to configure a measurement gap pattern such that sufficient amount of the reference signals to be used for said inter-frequency measurement fall in measurement gaps of the measurement gap pattern. 
     
     
       24. The user equipment of  claim 19 , wherein the memory contains instructions executable by the processor whereby the user equipment is configured to receive the indication in a manner that is transparent to the radio network node. 
     
     
       25. The method of  claim 1 , wherein the inter-frequency measurement is a positioning measurement that the user equipment is going to perform on a frequency different than that of the user equipment's serving cell. 
     
     
       26. The method of  claim 1 , wherein said received indication indicates that the user equipment needs a particular one of different pre-defined measurement gap patterns for performing the inter-frequency measurement, by explicitly indicating an index mapped to that particular pattern. 
     
     
       27. The method of  claim 1 , wherein the inter-frequency measurement is a measurement whose performance produces a result based on which the user equipment itself, or a positioning node in the wireless communication system, determines a geographical position of the user equipment. 
     
     
       28. The radio network node of  claim 7 , wherein the inter-frequency measurement is a positioning measurement that the user equipment is going to perform on a frequency different than that of the user equipment's serving cell. 
     
     
       29. The radio network node of  claim 7 , wherein said received indication indicates that the user equipment needs a particular one of different pre-defined measurement gap patterns for performing the inter-frequency measurement, by explicitly indicating an index mapped to that particular pattern. 
     
     
       30. The radio network node of  claim 7 , wherein the inter-frequency measurement is a measurement whose performance produces a result based on which the user equipment itself, or a positioning node in the wireless communication system, determines a geographical position of the user equipment. 
     
     
       31. The method of  claim 1 , further comprising determining a measurement gap pattern for performing the inter-frequency measurement for positioning, and signaling to the user equipment information to initiate use of the determined measurement gap pattern. 
     
     
       32. The radio network node of  claim 7 , wherein the memory contains instructions executable by the processor whereby the radio network node is configured to determine a measurement gap pattern for performing the inter-frequency measurement for positioning, and signal to the user equipment information to initiate use of the determined measurement gap pattern. 
     
     
       33. The method of  claim 13 , further comprising in response to receiving the indication, determining the measurement gap pattern and using the measurement gap pattern to perform the inter-frequency measurement for positioning. 
     
     
       34. The user equipment of  claim 19 , wherein the memory contains instructions executable by the processor whereby the user equipment is configured to, in response to receiving the indication, determine the measurement gap pattern and use the measurement gap pattern to perform the inter-frequency measurement for positioning.